Pericardium is a layer of connective tissue membrane that tightly wraps around the heart. In epicardial ablation, it is necessary to manually open a path through the pericardium tightly around the heart, in order to let the ablation catheter to access the space between the pericardium and the outwall of heart to conduct ablation.
There are a great diversity of pericardium puncture equipments on market. For example, Chinese patent CN00257117.X disclosed a type of noninvasive pericardium puncture needle, which comprises an outer sheath, an inner needle, and an end cap. The outer sheath is a flexible hollow tube that accommodates the inner needle. The inner needle is a solid puncture needle, which is fixed to the distal end of the outer sheath by the end cap. Once the pericardium is pierced by the needle, the needle is then withdrawn. The outer sheath continues advancing into the pericardium, so that the pericardial effusion can be extracted or drugs can be injected.
However, most of existing puncture needles are straight needle structure. In clinical operations, such a structure often pierces insufficiently and leads to puncture failure, or sometimes it tends to over-pierce and hurts the heart.